Intraocular dispersion of perfluorocarbon liquids in silicone oil

PURPOSE: To report one case of intraocular emulsification of perfluorocarbon liquids (PFCLs) and silicone oil after vitrectomy surgery. DESIGN: Interventional case report. METHODS: Retrospective review of the clinic, and surgical record of a 39-year old female referred for persistent retinal detachment after vitrectomy surgery; PFCLs and silicone oil were left in the eye at the end of the surgery. RESULTS: There was intraocular emulsification of PFCLs into silicone oil. Electron microscope examination of the silicone oil surgically extracted from the eye demonstrated emulsification of small PFCL bubbles into the silicone oil. CONCLUSION: Perfluorocarbon liquids are surgical tools. They should be completely removed from the eye at the end of the surgery; PFCLs and silicone oil tend to emulsify together, originating an opaque fluid, which contains both silicone oil and dispersed PFCL bubbles.     

Interactions of perfluorocarbon liquids and silicone oil as characterized by mass spectrometry

Background Perfluorocarbon liquids (PFCL) are used extensively in complex vitreoretinal surgery, sometimes before the placement of silicone oil (SiO). We suspected that PFCL and SiO interact physically when in opposition, potentially making their removal more difficult. The nature of some of these interactions was explored using a mass spectrometric approach in in-vitro and in-vivo samples.Methods We incubated silicone oil (1,000 or 5,000 centistokes viscosity) and PFCL [perfluoro-n-octane (PFO) or perfluorotributylamine] together in vitro for 6 months and performed electron impact ionization mass spectrometry (EIMS) on the PFCL to characterize interactions between the liquid phases. Packaged samples of PFCL served as controls. We also examined in vivo samples of PFO which had been retained in human eyes for several months prior to surgical removal.Results Perfluorocarbon liquids packaged for surgical use all contain SiO in trace amounts, possibly as a manifestation of the processes used in their manufacture. Furthermore, all PFCLs incubated with SiO showed much more prominent contamination with SiO molecular fragments. PFCL was found in the SiO phase of eyes in which both liquids were present for extended periods of time. The EIMS analysis of in vivo samples suggested that proteins coat PFCL droplets, forming micelle-like structures.Conclusion Medical-grade PFCLs contain small amounts of SiO, and PFCLs dissolve small amounts of oil into solution over time. Interactions between retained vitreous substitutes may have clinical relevance.Presented, in part, at the XXII Meeting of the Club Jules Gonin, Taormina, Sicily, 2000The authors have no proprietary interest relevant to this study     

Combined use of partially fluorinated alkanes, perfluorocarbon liquids and silicone oil: an experimental study

BACKGROUND: Partially fluorinated alkanes (FALKs) are a new class of substances which can be used in vitreoretinal surgery as an intraoperative tool and as a long-term tamponade. The aim of this in vitro study was (1) to investigate the solubility of FALKs in silicone oil during direct exchange, (2) to study their combined use and solubility in PFCLs, (3) to evaluate their lipophilic properties and (4) to investigate the possibility of preparing "heavy silicone oil". METHODS: (1) Four different FALKs (F6H6, F6H8, O44 and O62) were directly exchanged with silicone oil (5,000 mPas). The dissolved amount of fluorocarbons in the removed silicone oil was determined by gas chromatography and by gravimetry. Furthermore, the diffusion phenomena during the exchange process were studied. (2) The behaviour of FALKs in PFCLs was investigated and the solubility of the resulting mixtures in silicone oil was measured. (3) The solubility of FALKs and PFCLs in native olive oil was analysed. (4) Different FALKs were added to silicone oil and measurements of the resulting specific gravity and the viscosity were performed. RESULTS: (1) FALKs dissolved in silicone oil up to the following values: F6H6=45 m%, F6H8=54 m%, 044=100 m%, O62=18 m%. (2) FALKs dissolved in PFCL, thereby changing the physicochemical properties of PFCL depending on the type of FALK and ratio used. (3) The lipophilic properties of FALKs and PFCLs could be characterized by their dissolution in native olive oil (F6H8=23.4 m%, 044=16.7 m%, F6H6=12.3 m%, 062=5.3 m%, PFD=1.1 m%, PFO=0.6 m%). (4) It was possible to prepare "heavy silicone oil" e.g. by adding 30 vol% F6H8, resulting in a specific gravity of 1.08 g/ml, or by adding 80 vol% 044, resulting in a specific gravity of 1.25 g/ml, but decreasing the viscosity of the mixtures dramatically. CONCLUSION: (1) If FALKs are used as an intraoperative tool, a direct exchange with silicone oil should be avoided owing to their capacity to dissolve in silicone oil, resulting in a mixture with unpredictable properties. (2) A combined use with PFCLs and silicone oil is possible, if the right ratio is chosen. (3) The solubility of FALKs in native olive oil may be an indicator for their tissue penetration and may render feasible their use as a long-term tamponade. (3) "Heavy silicone oil" preparation using FALKs is possible, but the mixture needs further evaluation in terms of emulsification, mobilization of oligosiloxanes, tissue penetration and long-term stability.     

Fibroblast behavior at aqueous interfaces with perfluorocarbon, silicone, and fluorosilicone liquids

Perfluorocarbon, silicone, and fluorosilicone liquids with potential for use as vitreous substitutes in the management of complex retinal detachment were evaluated for surface reactivity by assessing the behavior of anchorage-dependent fibroblasts plated at the phase boundary between these compounds and culture medium. Low-viscosity perfluorcarbons were alumina-treated to remove polar impurities. On perfluorodecalin, perfluorodimethylcyclohexane, perfluorotrimethylcyclohexane, perfluoroethylcyclohexane, perfluorooctane, perfluoroperhydrophenanthrene, perfluoromethyladamantane, perfluorodimethyladamantane, the highly viscous perfluoropolyether liquids Krytox TLF7067 and 6354, and dimethylsiloxane liquids of a variety of viscosities, most cells did not attach; the few that did attach exhibited minimal spreading behavior and did not achieve the flattened spindle-shape morphology which is a prerequisite to normal proliferative activity. Conversely, on perfluoromethyldecaline, perfluorofluorene, perfluorotributylamine, the perfluoropolyether K-6 hexamer, trifluoropropylmethylsiloxane (fluorosilicone), and diphenyldimethylsiloxane, some cells became fusiform-shaped and exhibited proliferation, the extent of which varied with the compound. The association of alumina treatment of perfluorocarbon liquids with a reduction in cell growth was indicative of a relationship between the presence of residual hydrogen-containing impurities and the capacity for cellular attachment and growth. This correlation was demonstrated also in experiments in which cell attachment and growth was facilitated by the addition of hydrogen-rich monohydroperfluorooctane to alumina-treated perfluorooctane. In conclusion, evidence for the presence of surface active impurities in liquid vitreous substitute materials can be obtained by observing the behavior of attachment-dependent cells plated at the boundary between these compounds and culture medium.     

复杂性视网膜脱离术中应用过氟化碳的临床疗效分析

目的 分析过氟化碳液体在玻璃体切除术中的治疗效果,以提高复杂性视网膜脱离的治愈率。方法 分析复杂性视网膜脱离７６只眼在玻璃体切除术中应用过氟化碳液体的临床效果及并发症,对合并 严重增殖性玻璃体视网膜病变（ＰＶＲ）的视网膜脱离５４只眼及巨大裂孔视网膜脱离１１只眼的术后复位率及术后视力分别进行统计。结果 ７６只眼中,术后视网膜复位７０只眼（９２．１％）;术后视力〉０．０２者６９只眼（９０．８％）,其中     

New technique for removal of perfluorocarbon liquid related sticky silicone oil and literature review

AIM: To investigate the safety and efficacy of sticky silicone oil (SSO) removal using a 22-gauge vein detained needle and inner limiting membrane (ILM) wrap-and-peel technique.METHODS: This retrospective consecutive case series reviewed the records of patients with a history of retinal detachment who had received silicone oil and perfluorocarbon liquid (PFCL) as intraocular tamponades. Patients were included in the analysis if they exhibited SSO remnants during silicone oil removal. The aspiration of most of the SSO remnants was performed by a 22-gauge vein detained needle. The small amounts of droplets adhered to the macula and epi-macular membrane were subsequently removed by the ILM warp-and-peel technique. The anatomical and functional outcomes, and postoperative complications were recorded. In vitro experiments were performed to simulate the formation of SSO remnants in four groups.RESULTS: Of 711 patients who underwent silicone oil removal during the study period, 9 patients exhibited SSO remnants and underwent follow-up for at least 3mo. Seven eyes (78%) underwent the ILM wrap-and-peel technique to completely remove small droplets of SSO that were glued to the macula and epi-macular membrane. No obvious complications occurred. Postoperative optical coherence tomography revealed normal retinal structure in all patients. In vitro analyses showed that balanced salt solution and prolonged vibration (for 1wk) had the strongest effects on silicone oil and PFCL compound opacities.CONCLUSION: SSO remnants could be removed in an intact manner and without complications, using a vein detained needle-assisted and ILM wrap-and-peel technique. The findings suggest that PFCL and infusion fluid should be completely removed before silicone oil injection to prevent SSO formation.     

The biocompatibility of silicone, fluorosilicone and perfluorocarbon liquids as vitreous tamponades. an ultrastructural and immunohistochemical study

PURPOSE: To investigate the interactions occurring at the interface between some currently used vitreous tamponading substances and the ocular tissues, in an early follow-up after surgery. METHODS: Adult albino rabbit eyes underwent vitrectomy and were injected intravitreally with silicone oils at 1,000 or 3,000 cSt, fluorosilicone oil and perfluorodecalin. Different morphological techniques (light microscopy, scanning and electron microscopy, immunohistochemistry) were applied. RESULTS: All the tested materials, although non-toxic, penetrate the ocular tissues also at the anterior segment level, and in the long-term follow-up this can yield functional impairment. No massive inflammation has been detected in the zones in contact with the materials, but immunoglobulins and complement fractions are anyway present in the stroma of various tissues and around the droplets of emulsified materials, suggesting a local immune reaction. CONCLUSIONS: Data from this study confirmed that a permanent vitreous substitute, showing a perfect biocompatibility, still does not exist. The indication to remove the tamponading substance within 2 months after the surgery emerges from this investigation, confirming previous studies. Despite some negative features, silicone oil still appears the most biocompatible material for vitreous replacement.     

Intraoperative perfluorocarbon liquids in the management of proliferative vitreoretinopathy

Three low-viscosity perfluorocarbon liquids were used intraoperatively for hydrokinetic manipulation of the retina during vitreous surgery for retinal detachment with advanced proliferative vitreoretinopathy. All 23 patients had massive proliferative vitreoretinopathy (Grade D, Retina Society classification), and 16 (69.6%) had Grade D-3 with a closed-funnel configuration. In 21 eyes the retina could be flattened intraoperatively by perfluorocarbon liquids without requiring posterior retinotomy for internal drainage of subretinal fluid. The temporary mechanical fixation of the retina provided by this tool facilitated the removal of epiretinal membranes and release of traction. Fifteen eyes (65.2%) maintained long-term retinal reattachment with follow-up of six months or more. These liquids are useful adjuncts in the management of retinal detachment with severe proliferative vitreoretinopathy.     

Microbial growth in various perfluorocarbon liquids.

A prospective in vitro study was conducted to investigate the potential for various perfluorocarbon liquids to support the growth of microbes, which may be introduced into these liquids as contaminants during intraocular surgery. Perfluorodecaline, perfluoro-noctane, and perfluorophenanthrene were tested for the growth of Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans by using tryptone soy broth, pancreatic digest of casein, and Sabouraud broth as culture media for up to 10 days. No microbial growth was observed in any of these perfluorocarbon liquids. Perfluorocarbon liquids do not promote microbial growth. Thus, they do not increase the risk of endophthalmitis in vitreoretinal surgery.     

Effect of gravity in long-term vitreous tamponade: in vivo investigation using perfluorocarbon liquids and semi-fluorinated alkanes

Purpose In order to investigate whether gravity is the reason for retinal degeneration in long-term vitreous tamponade, perfluorohexyloctane (F6H8), perfluorodecalin (PFD), and a mixture of F6H8/PFD were compared. Materials and methods Each group of 5 rabbits received a 3-month tamponade with either PFD (pure) (1.93 g/cm³), F6H8 (pure) (1.33 g/cm³), or a 1:1 mixture of F6H8/PFD (1.62 g/cm³). Electroretinograms (ERG) were performed pre- and postoperatively. Lower and upper retinal areas were compared using immunohistochemical methods. Transmission electron microscopy was performed to investigate alterations in the photoreceptors. Results All three substances were tolerated well in rabbit eyes for up to 3 months. Dispersion was seen earliest with PFD and latest with pure F6H8. None of the substances demonstrated inflammatory reactions or vascular alterations. ERGs were not considerably altered with any of the substances. Histology of the retina showed alterations in the cell counts within the inner and outer nuclear layer that were not attributable to the gravity of the tamponading agent. Conclusion In contrast to previously published work, this study did not detect any tamponade-related structural damage of the retina after a 3-months tamponade in the rabbit model. Based upon this study, we conclude that gravity might not be causally linked to retinal damage. W. Hiebl and H. Meinert are employees of Fluoron. All other authors have no financial interest in the data presented.     

The use of perfluorocarbon liquids in diabetic vitrectomy.

Three eyes of 3 patients were operated on for severe proliferative diabetic retinopathy with tractional and/or rhegmatogenous retinal detachment using perfluoro-n-octane as temporary tamponade. The perfluorocarbon was removed at the end of the procedure. Intraocular tamponade was provided by a long-acting gas in all eyes. The intraoperative use of perfluorocarbon effectively facilitated retinal flattening and endophotocoagulation. Anatomical success was obtained in all 3 cases, with a minimum follow-up of 10 months. Visual acuity improved in all eyes. The main advantages of perfluorocarbon are that it enables easy flattening of the posterior retinal folds and effective endophotocoagulation with good visual conditions.     

Experimental study on antiviral activity of silicone oil in vitro

OBJECTIVE: To study the antiviral activity of silicone oil against herpes simplex virus-1 (HSV-1) in vitro. METHODS: (1) TCID(50) (Tissue culture infectious dose 50% endpoint) of HSV-1 was titrated. (2) The Hela cells were placed in a 96-well plate. (3) The virus was diluted by 100TCID(50), 50TCID(50), 30TCID(50), 10TCID(50), and 1TCID(50) individually. (4) Each of the five different concentrations of virus was inoculated into 16 wells. Of the 16 wells, 0.1 ml silicone oil was added to eight of them as the experimental group, and the other eight wells were used as controls. (5) Sixteen additional wells were added: silicone oil and maintenance media were added to eight wells, and only maintenance media to the other eight wells. RESULTS: (1) The cytopathic effect (CPE) of wells inoculated with 30TCID(50) combined with silicone oil was significantly less than that of the viral control at 32 hours (P < 0.01), and the same results occurred in group 10TCID(50) combined with silicone oil at 45 hours (P < 0.01) and group 1TCID(50) combined with silicone oil at 51 hours (P < 0.01). (2) In the viral control, the cells in 30TCID(50), 10TCID(50) and 1TCID(50) had pathological changes at 45, 58 and 58 hours respectively. (3) The cells of either the viral control group or group 50TCID(50) and 100TCID(50) had pathological changes at 32 hours (P > 0.05). CONCLUSION: Silicone oil has an antiviral function against HSV-1. The antiviral effect of silicone oil is correlated with concentration of virus.     

硅油抑制单纯疱疹病毒1型的体外实验研究

目的通过体外实验的方法研究硅油对单纯疱疹病毒1型(HSV-1)的抑制作用。方法(1)滴定HSV-1型TC ID50。(2)培养Hela细胞并接种于96孔板。(3)将HSV-1原液分别稀释为100 TC ID50、50 TC ID50、30 TC ID50、10 TC ID50和1 TC ID50。(4)将上述各浓度的HSV-1分别加到长满Hela细胞的96孔板中,每个浓度加到16个孔,其中8个孔另加0.1 mL硅油作为实验组,其余8个作为对照组。(5)再取8个孔加维持液和0.1 mL硅油作为实验组,8个孔只加维持液作为对照组。结果(1)实验后32 h的30 TC ID50实验组、实验后45 h的10 TC ID50实验组、实验后51 h的1 TC ID50实验组细胞病变均明显少于对照组(P<0.01)。(2)在病毒对照组中,30 TC ID50、10 TC ID50和1 TC ID50孔中细胞分别于实验后45 h、58 h和58 h发生100%病变。(3)50 TCID50对照组和实验组以及100 TCID50对照组和实验组细胞于实验后32 h发生100%细胞病变(P>0.05)。结论在体外实验中,硅油对HSV-1有明显抑制作用。其抑制作用大小与病毒的浓度有一定关系。     

氟碳液体眼科实验研究和临床应用

氟碳液体自1987年Stanley Chang首次在玻璃体视网膜手术中应用已20a,氟碳液体在玻璃体视网膜手术中的作用相当于粘弹剂在眼前段手术中的作用.20a来,氟碳液体在玻璃体视网膜手术中的应用范围不断扩大,对氟碳液体的基础研究也没有停止,现就氟碳液体在眼科的实验研究和临床应用作一综述.     

全氟化碳液体在孔源性视网膜脱离手术中的应用

目的　探讨全氟化碳液体在孔源性视网膜脱离玻璃体切割手术中的应用。方法　对 2 0 0 0年 6月～ 2 0 0 3年6月因孔源性视网膜脱离行玻璃体手术并在手术中使用全氟化碳液体的 94例 95眼进行回顾总结。结果　术后视网膜复位 85眼 ( 89 4% )。术后视力提高 76眼 ( 80 % ) ,视力无改变 12眼 ( 12 6% ) ,视力下降 7眼 ( 7 4% )。术后前房全氟化碳液体残留 3眼 ,玻璃体腔内全氟化碳液体残留 2眼 ,患者随访过程中未发现对角膜、视网膜及眼压产生影响。结论　全氟化碳液体作为孔源性视网膜脱离手术中的暂时性眼内填充物是安全有效的。     

硅油填充眼的白内障超声乳化联合硅油取出术

目的：探讨玻璃体视网膜手术联合硅油眼内填充术后并发性白内障行白内障超声乳化和/或人工晶体植入联合硅油取出术的临床效果。方法：对22例22眼硅油填充术后并发性白内障进行白内障超声乳化联合硅油取出手术,其中9例通过巩膜隧道切口植入硬性人工晶体,3例通过角膜切口植入折叠人工晶体,10例未植入人工晶体。结果：22例手术中后囊膜保持完整,除10例因高度近视、视网膜条件很差或再发视网膜脱离而未植入人工晶体外,蓁均顺利植入人工晶体。术后5例发生角膜水肿,均在术后3～7天内消退。硅油取出顺利。3例术中发现限局性网脱,行视网膜复位后,2例C2F6气体填充后2周再发网脱,1例再次硅油填充视网膜保持复位。视力除3例再发网脱外,其余均达到玻璃体手术后最佳视力。结论：硅油填充眼合并白内障行白内障超声乳化联合硅油取出手术不仅安全、有效、而且可减少病人多次手术的痛苦。